### Home > A2C > Chapter 12 > Lesson 12.1.4 > Problem 12-64

12-64.

Write each series in sigma notation and find the sum or an expression for the sum. Homework Help ✎

47 + 34 + 21 + … + (−83)

3+10 + 17 + … + (7

*n*− 4)

What is the expression for the sequence?

How many terms are there in the series?

One possible answer:

Instead of going up to a specific term, this series sums up the first *n* terms of the sequence given in parentheses.